momentum of shell?

Question

A 5.0 kg shell is moving at 200 m/s south. The momentum of the shell is??

a) 400 east
b) 6000 north
c) 1000 south
d) 150 south
e) 1020 south

please help, I don't understand this, thank you!

Answer 1

Momentum is m*v.

(Don't be confused about what kind of shell this is. I thought for a while that maybe it was a rolling thin-walled object but no radius is given. So it must be just some sea-shell.)

m*v* = 5 kg*200 m/s = 1000 kg*m/s

And momentum is a vector so it has a direction - the same direction as the velocity.